Generate a datmatrix label from input

make-datamatrix-label-pdf.py

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.11"
# dependencies = [
#     "ppf.datamatrix",
#     "reportlab",
#     "setuptools",
# ]
# ///

import argparse
from io import BytesIO
from reportlab.pdfgen.canvas import Canvas
from sys import stdin, stdout
from ppf.datamatrix.datamatrix import DataMatrix

padding_pct = 15
width = 1.0
height = 1.0
units = "inches"

INCHES_TO_POINTS = 72


def draw_barcode(c: Canvas, width: float, height: float, value: str):
    dmtx = DataMatrix(value).matrix

    rows = len(dmtx)
    px = width * (1 - (2*padding_pct) / 100) / rows

    initial = padding_pct / 100 * height
    y = height - initial
    for row in dmtx:
        x = initial
        for col in row:
            if col:
                c.rect(x, y, px, -px, fill=1, stroke=0)
            x += px
        y -= px

    c.showPage()


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("infile", nargs="?", type=argparse.FileType("r"), default=stdin.buffer)
    parser.add_argument(
        "outfile", nargs="?", type=argparse.FileType("wb"), default=stdout
    )
    parser.add_argument(
        "--width", type=float, default=width, help="width in %s" % units
    )
    parser.add_argument(
        "--height", type=float, default=height, help="height in %s" % units
    )
    args = parser.parse_args()

    w = args.width * INCHES_TO_POINTS
    h = args.height * INCHES_TO_POINTS

    io = BytesIO()
    c = Canvas(io, pagesize=(w, h))
    c.setFillColorRGB(0, 0, 0)

    for line in args.infile:
        draw_barcode(c, w, h, line.strip())

    c.save()

    args.outfile.write(io.getbuffer())
    args.infile.close()
    args.outfile.close()